Estudio de la variación de masa por unidad de superficie a 400°C en una

Two specific clinical tasks were selected for demonstrating automated instruction functionality within BodyExplorer. The motivation for selecting these clinical tasks was previously defined in

Section 2.5.2. The following sections describe the design specifications for creating the Cricoid Pressure Learning Module and the Medication Administration Learning Module.

3.3.3.1 Cricoid Pressure Learning Module Design Specifications

Development of the Learning Module was performed by consulting the literature on applying cricoid pressure and under clinical guidance from subject matter experts (SMEs). The SMEs consulted were Board Certified Anesthesiologists and Anesthetists at the University of Pittsburgh School of Medicine and School of Nursing. The primary SMEs were Dr. David Metro, Dr. Steven Orebaugh, and Dr. John O’Donnell. Under the guidance of the literature and SMEs, the following primary design specifications were determined:

1. The module should be able to distinguish when pressure is applied to the correct and incorrect areas of the neck.

2. Applied pressure (or force) should be held within the literature-defined pressure range. 3. Applied pressure (or force) should be held from the administration of the anesthetic

medications until after successful endotracheal intubation has been verified.

4. Instruction should be provided to locate the cricoid cartilage and with respect to how much pressure (or force) to apply.

From these primary design specifications and further discussions with our clinical SMEs, the following testable engineering requirements were established:

1. The measurement system should detect and differentiate whether a user is pressing on the thyroid or cricoid cartilage when at least 10N of force is applied to each structure. 2. The measurement system should be able to measure applied force to the cricoid

3. Measurement of force applied to the cricoid cartilage should not drift more than ±2N when constant force is applied for 30 seconds over the range of 0-50N.

Engineering requirement (1) addresses the primary design specification (1) identified by the SMEs. The thyroid and cricoid cartilage are key cartilage elements of the upper airway and are palpable externally on the anterior neck. The entire structure is sometimes referred to as the Adam’s apple in deference to a pronounced gender difference in the prominence of the structure with males more prominent than females. The v-shaped notch on the cephalad rim of the thyroid cartilage forms the thyroid notch. This thyroid notch is the first and most cephalad cartilage surface landmark identified when using a three-finger technique with the cricoid cartilage being most caudad. After locating the thyroid notch with the index finger, the body of the thyroid cartilage is palpated with the middle finger and thumb. Moving caudad, midline and lateral structures are palpated. Immediately inferior to the caudad rim of the thyroid, a depression or space is felt. This depression represents location of the membrane between the cricoid and thyroid cartilages and is described as the crico-thyroid membrane. Again moving caudad, the hard, cartilaginous structure immediately inferior to the cricothyroid membrane is the cricoid cartilage. The minimal number of cartilaginous structures to distinguish between is 2—the thyroid cartilage and the cricoid cartilage—when performing the progression to locate the cricoid cartilage.

Engineering requirements (2) and (3) address the primary design specifications (2) and (3), respectively, identified by the SMEs and in the literature. The amount of force to apply is about 10 N when the patient is awake and 30-44N for a patient under anesthesia. The range was expanded slightly in the engineering requirements to ensure measurement accuracy outside the prescribed application range. The accuracy of ±2N was chosen based upon previous variance found among users during their attempts to apply cricoid pressure [82, 83].

To meet the engineering requirements for the Cricoid Pressure Learning Module, modifications were made to the original, bench-top prototype. The primary modifications included:

1. incorporating the system for measuring force applied to the cricoid cartilage into a mannequin’s neck,

2. adding functionality for differentiating touch applied to the thyroid and cricoid cartilage, and

3. adding automated instruction to teach a learner how to find the cricoid cartilage on the neck and apply the correct force to seal the esophagus to address primary design requirement (4).

Modifications (1) and (2) are described in Section 0, and modification (3) will be described in the chapter devoted to automated instruction development, Chapter 6.0 . Verification of system performance against the engineering requirements will be presented in Section 4.1.

3.3.3.2 Medication Administration Learning Module Design Goals

Development of the Learning Module for safe medication administration resulted from discussions with stakeholders and subject matter experts (SMEs) involved in clinical education. Observations of simulation scenarios and interviews with instructors and simulation technicians were performed to understand how current medication administration training is performed, specifically focusing on how simulation technologies are being utilized to assist in the training. We observed that during instances when medications were administered to full-body mannequins during simulations, the RFID tag systems for automatic recognition of injected drug simulants was not used when it was available. Often, the method for recording what was administered was done by a hand gesture from an instructor to a simulation technician operating the simulator, or verbalization of the medication

and amount given by the user—the accurate content of the syringe was not identified and the amount administered was quantified by an instructor looking at the syringe pre- and post-injection, if at all. When presenting initial work towards development of our method for detecting administered drug simulants at the 12th Annual International Meeting on Simulation in Healthcare, discussions with other stakeholders in clinical education supported our findings.

One of the reasons identified for not using the automatic system was that it did not work reliably. The RFID system for medication identification is comprised of RFID readers located in the left antecubital region (elbow) and the mouth of the FBM. The RFID reader detects the presence of a RFID tag that can be attached with Velcro to any syringe. The size of the RFID tag aside, the larger issue is that when multiple RFID-tagged syringes are adjacent to either RFID reader, the system cannot identify what syringe is doing the injecting during administration. This issue is problematic because administration of IV medication should be followed with a saline flush to ensure that the dose of medication entered the patient and is not sitting in the IV tubing outside the patient. As such, injections would require a minimum of 2 syringes adjacent to the site of injection—a case where the RFID system would fail at identifying administration automatically. To address the limitation of current methods for automatic detection of administered IV medications during training, and based upon discussions with SMEs, we developed the following primary design goals:

1. Administered IV medications should be identified only after they enter the mannequin. 2. Identification of administered IV medications should be accurate even when multiple

syringes of medications are present near the site of injection.

4. The volume and rate of injection of the administered medication should automatically update the mannequin’s physiology without instructor or technician intervention. Our previous research addressed these primary design goals [69], but did not quantify system performance. The following parameters will be evaluated to establish a baseline assessment of accuracy and to understand the limits of the Medication Administration Learning Module Sensor subsystem:

1. Accuracy of medication identification 2. Accuracy of measured volume